有没有一种在AsyncTask中显示AlertDialog的通用方法？

private AlertDialog alertDialog;

@Override
protected void onPreExecute() {
    super.onPreExecute();
    AlertDialog.Builder builder = new AlertDialog.Builder(context);
    builder.setTitle("提示");
    builder.setMessage("加载中...");
    builder.setCancelable(false);
    alertDialog = builder.create();
    alertDialog.show();
}

@Override
protected void onPostExecute(Void aVoid) {
    super.onPostExecute(aVoid);
    if (alertDialog != null && alertDialog.isShowing()) {
        alertDialog.dismiss();
    }
}